Since before the Shuttle’s retirement back in 2011 NASA has been looking towards building the next generation of craft that will take humans into space. This initially began with the incredibly ambitious Ares program which was set to create a series of rockets that would be capable of delivering humans to any place within our solar system. That program was cancelled in 2010 by President Obama and replaced with a more achievable vision, one that NASA could accommodate within its meagre budget. However not all the work that was done on that program was lost and the Orion capsule, originally intended to ride an Ares-I into space, made its maiden flight last week signalling a new era for NASA.
The profile for this mission is a fairly standard affair, serving as a shakedown of all the onboard systems and the launch stack as a whole. In terms of orbital duration it was a very short mission, lasting only 2 orbits, however that orbit allowed them to gather some key data on how the capsule will cope with deep space conditions. It wasn’t all smooth sailing for the craft as the mission was meant to launch the day before however a few technical issues, mostly to do with the rockets, saw NASA miss the initial launch window. However the second time around they faced no such issues and with the wind playing nice Orion blasted off for its twice around the world voyage.
When I first read about the mission I was curious as to why it was launching into such an unusual orbit. To put it in perspective the apogee (the point of the orbit furthest away from the earth) was some 5,800KM which is an order of magnitude higher than anything else in low Earth orbit. As it turns out this was done deliberately to fling the Orion capsule through the lower Van Allen belt. These belts are areas of potentially damaging radiation, something which all intersolar craft must pass through on their journey to other planets in our solar system. Since Orion is slated to carry humans through here NASA needs to know how it copes with this potential hazard and, if there are any issues, begin working on a solution.
The launch system which propelled the Orion capsule into orbit was a Delta-IV Heavy which currently holds the crown for the amount of payload that can be delivered to low Earth orbit. It will be the first and last time that we’ll be seeing Orion riding this rocket as the next flight, slated for launch towards the end of 2018, will be the Space Launch System. This is the launch system that replaced the Ares series of rockets when Obama cancelled the Constellation program and will be capable of delivering double the payload of the Delta-IV Heavy. It’s going to need that extra power too as the next Orion mission is an uncrewed circumlunar mission, something NASA hasn’t done in almost 5 decades.
It’s great to see progress from NASA, especially when it comes to its human launch capabilities. The Shuttle was an iconic craft but it simply wasn’t the greatest way to get people into space. The Orion however is shaping up to be the craft that might finally pull NASA out of the rut it’s found itself in ever since the Apollo missions ended. We’re still a while off from seeing people make a return to space on the back of a NASA branded rocket but it’s now a matter of when, and not if, it will happen.
It’s hard to believe that it was only 5 months ago that SpaceX launched its very first Dragon capsule that was part of the Commercial Resupply Services contract they had with NASA. It was an unqualified success with everything from the launch to capture and finally to docking going as smoothly as you could possibly expect. Even more impressive was the fact that they accomplished this feat no more than 5 months after their previous ISS rendezvous attempt aptly demonstrating that they are very capable of meeting their aggressive timelines, something which many hardened arm chair space nuts like myself were initially sceptical of.
Today brings news of another successful flight of the SpaceX Dragon capsule, dubbed CRS-2, which has just docked at the International Space Station. Just like previous missions it’s been loaded quite lightly carrying 677KGs of playload which is about 10% of its total combined (pressurized and unpressurised) capacity. The vast majority of this is taken up with science experiments with crew supplies and replacement parts making up the lesser half. This is also the first time that the unpressurised section of the Dragon capsule has been used which is where the spare station parts were contained. These will be unloaded during an EVA whilst the Dragon is docked at the ISS.
CRS-2’s flight up wasn’t without some significant drama that threatened to send it plummeting back to earth. Whilst the initial launch was fine and second stage separation was completed (an area in which SpaceX has had troubles in the past) 3 of the 4 rocket pods contained on the Dragon craft reported insufficient pressurization in their oxidizer system. This in turn triggered another safety system which stopped the solar panels from deploying, a safety mechanism designed to protect the craft in an unsuccessful booster stage separation scenario. In this state the Dragon would not be able to berth with the ISS and would likely end up plummeting back to earth in a most ungraceful fashion.
The Dragon’s internal systems were then overridden and the rocket pods were allowed to continue pressurizing. Shortly afterwards 2 rocket pods were deemed active and the solar panels were deployed. Not long after that all 4 rocket pods were reporting proper pressurization and were brought back online. Whilst not a catastrophic failure it did push back the schedule by a day meaning CRS-2 didn’t dock until early this morning.
With this most recent launch SpaceX has shown just how reliable they can be as they’ve hit a launch every 5 months for almost a year. It might not sound like much but comparing that to any other launch system demonstrates just how far SpaceX has come in the comparatively short time they’ve been a company. With this all in mind it’s looking pretty good that they’ll be able to make their 2015 deadline of putting people into orbit which, considering that the replacement from NASA is a long way off, is extremely impressive.