NASA is to revive the Apollo space capsule design to serve the international space station as a crew return vehicle.
The US space agency is under obligation to provide a crew return vehicle (CRV) for the ISS by 2006, and at the same time meet its own requirements for a replacement for the troubled shuttle fleet.
Plans for a new mini-orbital spaceplane (OSP) that would serve as both, have been under discussion for some time. But this would not come into service until well after the 2006 deadline.
This week, however, engineers close to the project told The Engineer that NASA is planning to use a tried and tested space capsule design, similar to that used in the Apollo programme as a stopgap measure to service the ISS beyond 2010.
Dennis Smith, OSP programme manager, said NASA’s contractor Northrop Grumman is looking at the Apollo capsule designs.
‘Theoretically you could use the Apollo as a stopgap measure [for the crew return vehicle]. We are pulling out all the old studies. We’re taking a fresh look at the Apollo capsule to see if it is reasonable. The trouble is, that moves funds away from the main vehicle and we probably couldn’t get that ready by 2010.’
The crew return vehicle is critical to increasing the size of the crew aboard the ISS from the present maximum of three to seven. Without those extra crew the station’s science goals cannot be achieved and the ISS will be seen by many as a failure.
NASA is under pressure from its international partners to uphold its obligations on the crew return vehicle. Russian Soyuz capsules will be used for the purpose until 2006.
To make matters worse the US Congress passed a law forbidding NASA from buying Soyuz after that date. The agency is now hoping that its new capsule will be ready in time. However if it is not, the future looks bleak for the ISS as it is only certified for 15 years of operation before it is due to be de-orbited.
This new capsule will be developed as part of the OSP programme. This week NASA released design details for the crew-only shuttle. The new plans reflect the reduced budgets that have led NASA to combine the development of an emergency crew rescue vehicle and its long-term shuttle replacement.
The surprise inclusion of an Apollo-like capsule in the latest design proposals indicates that NASA has realised further budget cuts will force it to simply revive and enhance existing technologies.
Of the four designs for the OSP two of them are also from past NASA programmes.
They are the HL-20 and the X-38 space planes NASA insiders have confirmed that the Apollo capsule option is the most likely to be developed in the short term. One engineer who will be working on the project said it would be delivered to the ISS by a launcher and could be ready by 2010.
A man-rated launcher which is safe enough to take men into orbit would be required further into the future to transport crew using the capsule to the ISS. The only launchers that could do the job are currently still on the drawing board, the Atlas V and Delta IV.
Eventually the man-rated launcher could also carry one of the spaceplane designs that NASA has also outlined.
The published OSP design details state that the craft must carry at least a crew of four. If the capsule carried only four it might be used in conjunction with Soyuz capsules to ensure a crew of seven.
Other design specifications are that it must be safer than the shuttle and the Soyuz capsule. The specifications also state that the OSP should take less time to prepare than the shuttle, and launch more often.
Finally, like the existing Soyuz capsules. the OSP CRV will have to be replaced every six months. It is expected to be used from 2010 until 2020, assuming the ISS is still in orbit by then.