The Outer Space Treaty, which has been signed and ratified by over a hundred countries, declares that space should be a peaceful domain, free of weapons and violence. There are numerous reasons for this however the most critical of these is avoiding the horrendous plague that is Kessler syndrome, the point at which our near earth orbits are so littered with space junk that launching anything becomes next to impossible. At the same time however the lack of an overt weapons capability in space leads to all sorts of whacky theories about military operations in space, fuelled by the lack of public data on classified missions. The latest of which is the mysterious Kosmos-2499 satellite which some are theorizing is Russia’s latest anti-satellite weapon.
Kosmos-2499 attracted the attention of numerous conspiracy theorists due to it’s semi-mysterious launch. Quite often classified payloads are launched alongside regular ones in order to hide their true nature and this was the case with Kosmos-2499, launching with 3 other communications satellites (Kosmos-2496~2498). It was initially tracked as space debris since the official launch manifest only listed 3 payloads, however shortly after Roscosmos confirmed that 4 satellites were launched on that particular rocket. This makes it an interesting, although not particularly unusual, launch but its behaviour following launch is what really got the crazies whipped up.
It changed it’s orbit.
Satellites don’t typically change their orbit very much so when one does it often becomes a target of interest for stargazers. The X-37B is probably the most notable example of a satellite that was able to do this which was also a military craft although it’s orbit meant that, should it have any anti-satellite capabilities, it wouldn’t have the opportunity to use them. Kosmos-2499 is in a similar position however it was in a position to rendezvous with 2 pieces of space debris, namely the remnants of a previous launch vehicle and it’s own booster. This has then led to a flurry of speculation that Kosmos-2499 has satellite-killing capabilities ranging from things like a pellet gun to grappling arms that can detach solar panels. All things considered I think that’s a pretty unlikely scenario and the satellite’s purpose is likely a lot more mundane.
The other satellites launched alongside Kosmos-2499 were pretty small in stature, coming in at about 250kg each. It’s then highly likely that Kosmos-2499 doesn’t exceed this by much and so the capabilities that they can integrate into it a pretty limited. Also when you consider that it’s likely carrying with it a ton of propellant in order to complete these orbital transitions, including the approaches, then you’re even further limited in what kind of payload you can bring along for the ride. Most likely then Kosmos-2499 is a platform for Russia to test close approaches to other objects on orbit (I’d hazard a guess in an automated fashion) with a view to integrate such technology into future projects.
Whilst I sometimes enjoy letting the conspiracy nut part of my brain run amok on these things the truth of the matter is usually far more mundane than we’d think it to be. Doing things in space is awfully difficult and building in radical capabilities like the ones people are talking about really isn’t that feasible, or even sensible. Indeed the best counters to a military presence in space are most often ground based things that can be done far cheaper and with a lot less hassle than trying to create some kind of satellite killing space robot. Kosmos-2499 might be a bit mysterious but I doubt it’s purpose is that exotic.
The SR-71, commonly referred to as the Blackbird, was a pinnacle of engineering. Released back in 1966 it was capable of cruising at Mach 3.2 at incredible heights, all the way up to 25KM above the Earth’s surface. It was the only craft that had the capability to outrun any missiles thrown at it and it’s for this reason alone that not one Blackbird was ever lost to enemy action (although a dozen did fail in a variety of other scenarios). However the advent of modern surveillance techniques, such as the introduction of high resolution spy satellites and unmanned drones made the capabilities that the Blackbird offered somewhat redundant and it was finally retired from service back in 1998. Still plane enthusiasts like myself have always wondered if there would ever be a successor craft as nothing has come close to matching the Blackbird’s raw speed.
The rumours of a successor started spreading over 3 decades ago when it was speculated that the USA, specifically Lockheed Martin, had the capability to build a Mach 5 version of the Blackbird. It was called Project Aurora by the public and there have been numerous sightings attributed to the project over the years as well as a lot of sonic boom data gathered by various agencies pointing towards a hypersonic craft flying in certain areas. However nothing concrete was ever established and it appear that should the USA be working on a Blackbird successor it was keeping it under tight wraps, not wanting a single detail of it to escape. A recent announcement however points to the Aurora being just a rumour with the Blackbirds successor being a new hypersonic craft called the SR-72.
Whilst just a concept at this stage, with the first scaled prototype due in 2023, the SR-72’s capabilities are set to eclipse that of the venerable Blackbird significantly. The target cruise speed for the craft is a whopping Mach 6, double that of its predecessor. The technology to support this kind of speed is still highly experimental to the point where most of the craft built to get to those kinds of speeds (in air) have all ended rather catastrophically. Indeed switching between traditional jet engines and the high speed scramjets is still an unsolved problem (all those previous scramjet examples were rocket powered) and is likely the reason for the SR-72’s long production schedule.
What’s particularly interesting about the SR-72 though is the fact that Lockheed Martin is actually considering building it as the aforementioned reasons for the Blackbird’s retirement haven’t gone away. Whilst this current concept design seems to lend itself to a high speed reconnaissance drone (I can’t find any direct mention of it being manned and there’s no visible windows on the craft), something which does fit into the USA’s current vision for their military capabilities, it’s still a rather expensive way of doing reconnaissance. However the SR-72 will apparently have a strike capable variant, something which the Blackbird did not have. I can’t myself foresee a reason for having such a high speed craft to do bombing runs (isn’t that what we have missiles for?) but then again I’m not an expert on military strategy so there’s probably something I’m missing there.
As a technology geek though the prospect of seeing a successor to the SR-72 makes me giddy with excitement as the developments required to make it a reality would mean the validation of a whole bunch of tech that could provide huge benefits to the rest of the world. Whilst I’m sure the trickle down wouldn’t happen for another decade or so after the SR-72’s debut you can rest assured that once scramjet technology has been made feasible it’ll find its way into other aircraft meaning super fast air travel for plebs like us. Plus there will also be all the demonstrations and air shows for Lockheed Martin to show off its new toy, something which I’m definitely looking forward to.
When I first wrote about Planetary Resources early last year I was erring on the side of cautious optimism because back then there wasn’t a whole lot of information available regarding how they were actually going to achieve their goal. Indeed even their first goal of building and launching multiple space telescopes sounded like it was beyond the capabilities of even veteran players in this industry. Still the investors backing them weren’t the type to be taken for a ride so I figured they were worth keeping an eye on to see how they progressed towards their goal.
And boy have they ever:
The above video shows off one of their prototypes of the Arkyd-100 space based telescope. Now back when Planetary Resources first started talking about what they were going to do I wasn’t expecting something of this size. Indeed I don’t believe anyone has attempted to make a space based telescope that small before as you’re usually trying to amp up your light gathering potential with a large mirror. Still despite the relatively small mirror size they should be quite capable of doing the required imagery that will lead them to potential mineable asteroids.
Their communications set up is also highly intriguing as traditional space communications require large dishes and costly receiving equipment back here on earth. Planetary Resources are instead looking to use lasers for their deep space communications an idea that I didn’t think would be possible. A quick bit of research turns up this document from NASA’s Jet Propulsion Lab which goes into some detail about their feasibility and shockingly it appears to only be an engineering challenge at this point. How long it will take to turn it into something usable remains to be seen but considering Planetary Resources are looking to launch within the next couple years I’d hazard a guess that they’re already pretty close to getting it working.
Looking at all this you’d think I’d be ashamed of my initial scepticism but I’m not, I love it when people prove me wrong like this. Indeed the work that Planetary Resources are doing closely resembles that of the early days of SpaceX, a company which has gone on to achieve things that no other private company has done before. Given enough time it’s looking like Planetary Resources will be able to do the same and that gets me all kinds of excited.
Cast your mind back 5 months, where were you then? I can remember where I was quite clearly: I was in a hotel room in a city called Bandar Seri Begawan, the capital of Brunei. With nothing much else to do in town apart from drink coffee and swelter in the unrelenting heat I had made myself comfortable on the bed with my laptop and tenuous Internet connection so that I could witness history in the making. It was there that I saw SpaceX’s Dragon capsule being captured by the crew aboard the International Space Station and brought to dock with the ISS, becoming the first ever private craft to do so.
SpaceX, not wanting to falter with their goal of being able to rapidly turn around craft, has today achieved the same feat again and the very first of their official missions, dubbed CRS-1 (Commercial Resupply Service), has just docked at the ISS. Just like its predecessor the payload its taking up isn’t anything to get excited about being mostly crew supplies, materials for new and current experiments as well as hardware for ongoing maintenance of the station itself. Just like its predecessor it will also be bringing back some payload back with it once its completed its 2 week mission attached to the ISS, something which is still a unique capability of the Dragon capsule.
Whilst the mission might be fairly rudimentary its launch has been anything but. Those of us who tuned into the launch live stream on Monday were treated to a pretty spectacular show due to the launch happening at night. There was also a curious incident where one of the engines appeared to suffer some kind of failure with many news outlets reporting that one of the engines on the Falcon 9 had exploded during the first stage. The failure didn’t appear to affect the launch however with the comms chatter saying everything was nominal and with the Dragon arriving successfully you can’t really fault them.
In fact the “explosion” was actually part of a system designed to relieve pressure in the engine bay when an engine out occurred. The system was triggered as the control systems aboard the Falcon 9 detected a loss of pressure in engine 1 and shut down the engine which lead to those panels being ejected in a rather spectacular fashion. To put this all in perspective the Falcon 9 can make it into orbit with 2 of its engines failing in this fashion and for many of the previous missions it has actually throttled down 2 of its engines because the additional thrust isn’t required. Thus whilst this was unexpected it was not a situation that they hadn’t accounted for and it was actually a great demonstration of the Falcon 9’s engine out capability, something which is currently unique to it (other launchers, which are no longer flying, have had this functionality).
A separate payload that wasn’t part of the CRS-1 mission is the prototype satellite for Orbcomm which was released once the Falcon 9 entered its second stage of flight. Whilst the payload was successfully released it was unfortunately dropped into the wrong orbit, much lower than the one required. Officials have stated that this was due to the engine out causing the other 8 engines to compensate, making them burn for longer than what was originally calculated for. Whilst they might be able to salvage it using the onboard propellant (which will reduce the useful life of the craft significantly) it’s still something of a faux pas on SpaceX’s part. I’m sure that for the next lot of flights it won’t be an issue as SpaceX has a phenomenal track record for fixing this problems as soon as they become apparent.
Despite these issues it’s still a great achievement for SpaceX to go from first dock to the ISS to being an official re-supplier all within the space of 5 months. Whilst they won’t make the deadlines that they originally had planned for this year (CRS-2 has slipped to be no earlier than January 2013) they’re still moving at a blistering pace compared to nearly all other players in the space industry. For now they’ll be slipping into the routine of launching cargo missions but it won’t be long before they start sending people up alongside the cargo and that’s an incredibly exciting prospect.
The Hubble Space Telescope stands with the Shuttle as one of the most iconic space craft of the past 2 decades. It has been an amazing boon to science giving us images into the far reaches of space, revealing much about the universe that we would not have known without it. For all it has given us however it is starting to show its age after being in space for a continuous 22 years and the last decade has been dedicated to building a successor. Currently the craft lined up to replace it is the James Webb Space Telescope and whilst its a worthy replacement it’s nothing like the Hubble, for better and for worse.
You see Hubble really is a fully fledged observatory in space being able to capture several different wavelengths of light. This is why we’re able to get those gorgeous pictures out of it as the light it sees is pretty close to what our eyes can see. It’s not exact though as the various filters used to create the images are more aligned to detecting distinct spectral emissions so we end up with images made in what’s called the Hubble Palette. The JWST on the other hand is a pure infrared telescope which is great for studying distant and faint objects but is incapable of producing anything like the Hubble does. To really replace Hubble we’d need a telescope, or maybe even a couple specialized ones working in tandem, that covered a similar array of spectra.
Turns out the National Reconnaissance Office had a couple of these spare.
It might come as a bit of a surprise that the US Department of Defense (of which the NRO is a child agency) has a space program that rivals that of NASA in terms of scale and budget, but it has been that way for some time now. Of course their objectives are decidedly different with NASA being focused on science and exploration and the DoD more interested in the intelligence gathering prospects. It seems that as part of their spy satellite programs they have produced 2 telescopes with Hubble like capabilities that they no longer require (they have not been launched and returned as we have had no missions capable of performing such a task) and have gifted them to NASA. The question now is what to do with these 2 potential Hubble replacements, lest the gift be wasted.
Now these things aren’t exactly ready to fly satellites, they’re basically skeletons ready to be molded into whatever shape NASA wants them to be in. So the basics are there like the housing and the primary (and secondary, something Hubble didn’t have) mirror array but it’s missing crucial parts like the sensors, communication systems and I’m guessing stationkeeping equipment. So there’s a large parcel of work that’s already been done, and no doubt anyone who was looking to build a satellite would love to have this much done for them for free, but to actually get these things flight ready will take quite some time and, most importantly, some budget. If the required funds were found immediately NASA believes they’d be ready to launch no earlier than 2020, or a turnaround time of about 8 years.
Personally I believe that we’d be best served by configuring both telescopes to be identical and then launch them as a stereoscopic pair that could perform in space interferometry. This would allow us to surpass the capabilities of Hubble significantly and would open up imaging opportunities that just weren’t available otherwise. Of course we’d probably be better suited designing a whole new telescope with an even larger mirror array than the two combined but with NASA struggling to complete the JWST on time I can’t see that happening for anytime in the near future. Using these two proto-Hubbles would be an excellent solution for the interim however.
It’s not often that some like this happens so it will be very interesting to see what NASA does with these skeleton telescopes. I would love to see a visible spectrum telescope up there to replace the Hubble after it returns to Earth in a fiery blaze of glory but there are just as many other worthwhile goals for these little beauties. Whatever their fate I’m glad that they’re now in the hands of NASA as they’ll do a lot more good for mankind as science vessels than they ever would as spies.
In the short time that we’ve been launching stuff into orbit around our little blue marble we’ve made quite a mess of things up there. Sure it’s not that much of problem currently thanks to NASA tracking the most dangerous parts of it but the fact is that as time goes on the problem isn’t going to get better on its own. Whilst most space junk that’s close to earth or beyond geosynchronous will eventually burn up or leave our orbit for good the space in between there is littered with junk that will stay around from a couple decades to even a few centuries. It’s not exactly an easy problem to solve either as orbital mechanics aren’t exactly energy efficient, but that hasn’t stopped people from trying.
There are two factors that make cleaning up space junk difficult: the orbital speeds involved and the fact that most space junk doesn’t share an orbit. The first one is the reason that space junk is such a big problem in the first place. You see to stay in orbit you need to be travelling at some 26,000KM/h (Mach 26ish) and when you hit that speed small things start to become rather dangerous. The ESA has some good pictures of what hypervelocity impacts look like and should such an impact happen on a craft it’s usually the end of it, and the beginning of yet another debris field.
The orbits also pose a problem as any efficient space junk collector will need to change orbits often in order to be able to capture as much space junk as possible. Doing so requires either a lot of energy or an incredibly efficient engine (thus, lots of time) and there’s really nothing that solves either of these problems well when it comes to a space junk collector. The Swiss Space Centre still wants to have a crack at it though with their concept craft CleanSpace One:
The cleanup satellite has three major challenges to overcome, each of which will necessitate the development of new technology that could, in turn, be used down the road in other applications.
After its launch, the cleanup satellite will have to adjust its trajectory in order to match its target’s orbital plane. To do this, it could use a new kind of ultra-compact motor designed for space applications that is being developed in EPFL laboratories. When it gets within range of its target, which will be traveling at 28,000 km/h at an altitude of 630-750 km, CleanSpace One will grab and stabilize it – a mission that’s extremely dicey at these high speeds, particularly if the satellite is rotating. To accomplish the task, scientists are planning to develop a gripping mechanism inspired from a plant or animal example. Finally, once it’s coupled with the satellite, CleanSpace One will “de-orbit” the unwanted satellite by heading back into the Earth’s atmosphere, where the two satellites will burn upon re-entry.
In essence CleanSpace One is a simple capture and de-orbit craft, designed to be disposable. They’re looking to create a whole family of them that can cater to any kind of satellite and presumably looking to launch several at once in order to keep the cost down. Whilst such a craft would eliminate some space junk it doesn’t address the larger problem of those satellites not being managed properly in the first place, which I think is the core of the problem.
You see most of the junk satellites are still there because they weren’t designed with any kind of de-orbiting mechanism in them. The reasoning behind this is simple, such systems add cost to already expensive satellites and are therefore usually overlooked. There’s also a lot more maintenance and regulation required for such things as well like Hydrazine which is commonly used in such systems. It’d be far more cost effective to regulate that all new satellites have to have something like NanoSail-D attached to it as they’re relatively cheap and can de-orbit a satellite without the added hassles of current de-orbit systems.
I still commend the Swiss for being forward thinking with this issue however and realistically this is logical first step towards fixing the space debris problem. With experience they might be able to find clever ways to structure orbits for debris capture or devise better propulsion systems that will make more efficient collection possible. Developments in this area will also have flow on effects for other space programs as well as many of the technologies developed for something this will have dual uses elsewhere. Hopefully this will trigger other countries to start thinking about their own kind of space debris management system and eventually lead to an end to the mess that we created up there.
The USA has always been wary of China’s ambitions in space and I believe it’s mostly for all the wrong reasons. Sure I can understand that the fact that China’s space division is basically a wing of its military might be cause for concern, but the same could be said for the fact that the USA’s Department of Defense’s budget for space exploration exceeds that of NASA’s. Indeed the USA is worried enough about China’s growing power in space and other industries that there’s already been speculation that it could spark another space race. Whilst this would be amazing for a space nut like myself I really wouldn’t wish that kind of tension on the world, especially when the USA is struggling as much as it is right now.
Of course that tension is enough to spark all sorts of other speculation, like for instance the true nature of the mysterious X-37B’s mission. It’s payload bay suggested that it was capable of satellite capture, an attribute shared by it’s bigger cousin the Shuttle, but its previous orbits didn’t put it near anything and it didn’t really have enough delta-v capability to be able to intersect with anything outside a few degrees of its own orbit. However since then there’s been a couple launches and one of them is smack bang in the X-37B’s territory.
The craft in question is none other than China’s Tiangong-1.
Yesterday the BBC ran an article that speculated that the USA was using the X-37B to spy on Tiangong-1. Now initially I dismissed this as pure speculation, there are far easier ways for the USA to spy on a satellite (like using one of their numerous other satellites or ground based dish arrays) than throwing their still experimental craft up in a chase orbit. However checking the orbital information for both Tiangong-1 and the X-37B shows that they do indeed share very similar orbits, varying by only 0.3 of a degree in inclination and having pretty similar apogees and perigees. Figuring this is the future and everything should be a few Google searches away from certainty I set about finding out just how far apart these two satellites actually are to see if there was some possibility of it being used to spy on China.
To do this I used 2 different tools, the first being n2yo.com a satellite tracking website. This site allows you to input the satellites you want to track and then displays them on a Google map. Once I have that I can then use another tool, this time from findpostcode.com.au which shows me the distance between two points (which thankfully also takes into account the fact the earth isn’t flat). So firstly here’s a picture of the two orbits overlapped:
So as you can see they do indeed share very similar orbits but there does seem to be an awful lot of distance between them. Just how much distance? Well the second picture tells the full story:
Just over 14,000KM which is greater than the diameter of the earth. What this means is that if the X-37B was being used to spy on Tiangong-1 it would have to peer through the earth in order to see it, something which I’m pretty sure it isn’t capable of. Also if you look at the first picture you’ll also notice that Tiangong-1 actually passes over the USA as part of its normal orbital rotation, putting it well within the purview of all the ground observations that they have control of. I’ll note that the distance between Tiangong-1 and the X-37B won’t remain constant, but they will spend a good portion of their lives apart. Enough so that I don’t believe it would be particularly useful for reconnaissance. Additionally unless the USA knew which orbit that Tiangong-1 was going to use (possible, but we’re getting deeper into conspiracy territory here) then technically Tiangong-1 launched onto the X-37B’s orbit and not the other way around (it has not changed its orbit since the second launch, unlike it did the first time).
Honestly the idea that the USA was using the X-37B was definitely an interesting prospect but in reality there’s really no justification apart from conspiracy theory-esque hand waving. The USA has far better tools at their disposal to spy on China’s fledgling space industry than a single run experimental craft that’s only on its second flight. The orbits also put them at a fair distance apart for a good chunk of the time (as far as I can tell, at least) as well making it even less likely that the X-37B is being used for spying. Still it was an interesting idea to investigate, as is most things to do with the ever mysterious X-37B.
Debris in orbit are becoming one of the greatest challenges that we face as we become a space fairing species. You see by the simple fact that something is in orbit means that it has an incredible amount of potential energy, zipping around the earth at Mach 25 ready to wreck anything that might cross its path. Thankfully there’s quite a lot of empty space up there and we’re really good at tracking the larger bits so it’s usually not much of an issue. However as time goes by and more things are launched into orbit this problem isn’t going to get any better, so we need to start thinking of a solution.
Problem is that recovery of space junk is an inherently costly exercise with little to no benefits to be had. A mission to recover a non-responsive satellite or other spacecraft is almost as complex as the mission that launched said object in the first place, even more so if you include humans in the equation. Additionally you can’t send up a single mission to recover multiple other missions as typically satellites are on very different orbits, done so that they won’t collide with each other (although that has happened before). Changing orbits, known as a plane change, is extremely expensive energy wise and as such most craft aren’t capable of changing more than a couple degrees before their entire fuel supply is exhausted. The simple solution is to deorbit any spacecraft after its useful life but unfortunately that’s not the current norm and there’s no laws governing that practice yet.
It’s even worse for geostationary satellites as in that particular orbit things don’t tend to naturally deorbit over time. Instead anything in a geostationary orbit is pretty much going to be there forever unless some outside force acts on them. Geostationary orbits are also particularly valuable due to their advantageous properties for things like communication and location so the problem of space debris up there is of a much bigger concern. Thankfully most geostationary satellites have the decency to move themselves into a graveyard orbit (one just outside geostationary which will eventually see them flung from earth orbit) but this method isn’t guaranteed. Mass that’s already in orbit is incredibly valuable however and DARPA has been working on a potential solution to debris in geostationary orbit.
The DARPA Phoenix program is an interesting idea, in essence a in orbit salvager that cannibalizes other satellites’ parts in order to create new “satlets”. These new satlets won’t be anywhere near as capable as their now defunct donors were but they do have the potential to breathe a whole lot of life back into the hardware that’s just sitting there idle otherwise. Compared to a regular geosynchronous mission something like Phoenix would be quite cheap since a good chunk of the mass is already up in orbit. Such a mission can really only be done in geostationary orbit since all the satellites are in the same plane and the energy required to move between them is minimal. That is our most valuable orbit however so such a mission could prove to be quite fruitful.
Dealing with the ever growing amount of space debris that we have orbiting us is a challenge that we’ve still yet to answer. Programs like DARPA’s Phoenix though are the kinds of projects we’ll need to both reduce the amount of orbital junk we have as well as making the most out of the stuff we’ve already put up there. I’m really keen to see how the Phoenix project goes as it’d would be quite a step forward for on orbit maintenance and construction as well as being just plain awesome.
Whilst the Space Shuttle will always be one of the most iconic spacecraft that humanity has created it’s design was one of compromises and competing objectives. One of the design features, which influenced nearly every characteristic of the Shuttle, was the requirement from the Department of Defense that stipulated that the Shuttle needed to be able to launch into a polar orbit and return after a single trip around the earth. This is the primary reason for the Shuttle being so aeroplane like in its design, requiring those large wings so it has a long downrange capability so that it could return to its launch site after that single orbit. The Shuttle never flew such a mission, but now I know why the DoD required this capability.
It was speculated that that particular requirement was spawned out of a need to capture spy satellites, both their own and possibly enemy reconnaissance craft. At the time digital photography was still very much in its infancy and high resolution imagery was still film based so any satellite based spying would be carrying film on board. The Shuttle then could easily serve as the retrieval vehicle for the spy craft as well as functioning as a counter intelligence device. It never flew a mission like this for a couple reasons, mostly that a Shuttle launch was far more expensive than simply deorbiting a satellite and sending another one up there. There was also the rumour that Russia had started arming its spacecraft and sending humans up there to retrieve them would be an unnecessary risk.
The Shuttle’s payload bay was also quite massive in comparison to the spy satellites of the time which put further into question the DoD’s requirements. It seems however that a recently declassified spy satellite, called HEXAGON, was actually the perfect fit and could have influenced the Shuttle’s design:
CHANTILLY, Va. – Twenty-five years after their top-secret, Cold War-era missions ended, two clandestine American satellite programs were declassified Saturday (Sept. 17) with the unveiling of three of the United States’ most closely guarded assets: the KH-7 GAMBIT, the KH-8 GAMBIT 3 and the KH-9 HEXAGON spy satellites.
“I see a lot of Hubble heritage in this spacecraft, most notably in terms of spacecraft size,” Landis said. “Once the space shuttle design was settled upon, the design of Hubble — at the time it was called the Large Space Telescope — was set upon. I can imagine that there may have been a convergence or confluence of the designs. The Hubble’s primary mirror is 2.4 meters [7.9 feet] in diameter and the spacecraft is 14 feet in diameter. Both vehicles (KH-9 and Hubble) would fit into the shuttle’s cargo bay lengthwise, the KH-9 being longer than Hubble [60 feet]; both would also fit on a Titan-class launch vehicle.”
HEXAGON is an amazing piece of cold war era technology. It was equipped with two medium format cameras that would sweep back and forth to image an area, capturing an area 370 nautical miles wide. Each HEXAGON satellite carried with it some 60 miles worth of film in 4 separate film buckets which would detach from the craft when used and return to earth where they would be snagged by a capture craft. They were hardy little canisters too with one of them ending up on the bottom of an ocean but was retrieved by one of the navy’s Deep Submergence Vehicles. There were around 20 launches of the HEXAGON series of craft with only a single failure towards the end of the program.
What really surprised me about HEXAGON though was the resolution they were able to achieve some 30+ years ago. HEXAGON’s resolution was improved throughout its lifetime but later missions had a resolution of some 60cm, more than enough to make out people and very detailed images of say cars and other craft. For comparison GeoEye-1, which had the highest resolution camera on an earth imaging craft at the time of launch, is only just capable of a 40cm per pixel resolution (and that imagery is property of the USA government). Taking that into consideration I’m wondering what kind of imaging satellite the USA is using now, considering that the DoD appears to be a couple decades ahead of the commercial curve.
It’s always interesting when pieces of a larger puzzle like the Shuttle’s design start falling into place. Whilst it’s debatable whether or not HEXAGON (and it’s sister craft) were a direct influence on the Shuttle there’s enough coincidences to give the theory a bit of credence. I can see why the USA kept HEXAGON a secret for so long, that kind of capability would’ve been down right scary back in the 80’s and its reveal makes you wonder what they’re flying now. It’s stuff like this that keeps me obsessed about space and what we, as a species, are capable of.
The Internet as it stands today is the greatest revolution in the world of communications. It’s a technical marvel, enabling us to do many things that even up to a couple decades ago were firmly in the realms of science fiction. Indeed the incredible acceleration of technical innovation that we’ve experienced in recent history can be attributed to the wide reaching web that enables anyone to transmit information across the globe . So with the human race on the verge of a space revolution that could see a human presence reaching far out into our solar system a question burns away in the minds of those who’d venture forth.
How would we take the Internet with us?
As it stands currently the Internet is extremely unsuitable for inter-planetary communications, at least with our current level of technology. Primarily this is because the Internet is based off the back of the TCP/IP protocols which abstract away a lot of the messy parts of sending data across the globe. Unfortunately however due to the way these protocols are designed the transmission of data is somewhat unreliable as neither of the TCP/IP protocols make guarantees about when or how data will arrive at its destination. Here on Earth that’s not much of a problem since if there are any issues we can just simply request the data be sent again which can be done in fractions of a second. In space however the trade-offs that are made by the foundations of the Internet could cause immense problems, even at short distances like say from here to Mars.
Transmissions from Mars take approximately 3 minutes and 20 seconds to reach Earth since they travel at the speed of light. Such a delay is quite workable for scientific craft but for large data transfers it represents some very unique problems. For starters requesting that data be resent means that whatever system was relying on that data must wait a total of almost 7 minutes to continue what it was doing. This means unreliable protocols like the TCP/IP stack simply can not be used over distances like these when re-transmission of data is so costly and thus the Internet as it exists now can’t really reach any further than it already does. There is the possibility for something more radical, however.
For most space missions now the communication method of choice is usually a combination of proprietary protocols coupled with directed microwave communication. For most missions this works quite well, especially when you consider examples like Voyager which are 16 light hours from earth, however these systems don’t generalize very well since they’re usually designed with a specific mission in mind. Whilst an intrasolar internet would have to rely microwaves for its primary transmission method I believe that a network of satellites set up as anAldrin Cycler between the planets of our solar system could provide the needed infrastructure to make such a communications network possible.
In essence such satellites would be akin to the routers that power the Internet currently, with the main differences being that each satellite would verify the data in its entirety before forwarding it onto the next hop. Their primary function would also change depending on which part of the cycle they were in, with satellites close to a planet functioning as a downlink with the others functioning as relays. You could increase reliability by adding more satellites and they could easily be upgraded in orbit as part of missions that were heading to their destination planet, especially if they also housed a small space station. Such a network would also only have to operate between a planet and its two closest neighbors making it easy to expand to the outer reaches of the solar system.
The base stations on other planets and heavenly bodies would have to have massive caches that held a sizable portion of the Earth Internet to make it more usable. Whilst you couldn’t have real time updates like we’re used to here you could still get most of the utility of the Internet with nightly data uploads of the most updated content. You could even do bulk data uploads and downloads to the satellites when they were close to the other planets using higher bandwidth, shorter range communications that were then trickle fed over the link as the satellite made its way back to the other part of its cycle. This would be akin to bundling a whole bunch of tapes in a station wagon and sending it down the highway which could provide extremely high bandwidth, albeit at a huge latency.
Such a network would not do away with the transmission delay problems but it would provide a reliable, Internet like link between Earth and other planets. I’m not the first to toy with this kind of idea either, NASA tested their Disruption Tolerant Networking back in 2008 which was a protocol that was designed with the troubles of space in mind. Their focus was primarily on augmenting future, potentially data intensive missions but it could be easily be extended to cover more generalized forms of communication. The simple fact that agencies like NASA are already well on their way to testing this idea means we’re already on our way to extending the Internet beyond its earthly confines, and it’s only a matter of time before it becomes a reality.