Currently, the United States does not have a vehicle that would allow us to put people into space, but there are several efforts, says Space News from Nov. 13, to develop that capability. There is a lot of excitement about commercial efforts to get people into space, but so far the government effort has not attracted as much attention.
The government capsule is called the MPCV, and was formerly known as the Orion. Let's compare the MPCV to the earlier Apollo capsule to see if we are making progress. First, why does the capsule in development have such a dull name? NASA had a competition for a development contract for the crew capsule; a Lockheed proposal won the competition, and was named the Orion -- as a part of the Constellation program. When a new president was elected a lot of things had to change; the Constellation was canceled, but the Orion was quickly brought back in a series of un-cancellations. First it was brought back as an unneeded crew rescue vehicle and then as an exploration vehicle. Now it apparently duplicates the role of the commercial vehicles. Still, the Orion name was associated with the old Administration and had to go, and it was renamed the Multi-Purpose Crew Vehicle -- while someone figures out why it is being built.
* The MPCV should carry up to four people, with cargo replacing some of the people as needed. The earlier design of the vehicle had been downsized to four (allowing the other three positions possibly restored later?) so we will see if the MPCV will possibly carry more at some point. The MPCV should have 8.95 cubic meters (316 cubic feet) of usable volume with 19.56 cubic meters (691 cubic feet) of pressurized volume. Each person will have 2.24 cubic meters with this design.
* The Apollo Command Module carried three people in 6.2 cubic meters (207 cubic feet) of usable volume but pressurized a total of 10.3 cubic meters (343 cubic feet) the larger size accounts for volume containing avionics and stowage. So it is smaller than the MPCV, and it carried one fewer person (as currently planned). Each person will have 2.07 cubic meters to move around in.
* The Apollo Command Module weight and dimensions are given in the previous story. The weight of the MPCV is planned to be approximately 8913 kilograms (19650 pounds mass) so the MPCV will be about 3353 kilograms heavier.
* The Apollo Command Module was always flown with the Service Module attached; it contained a boost engine, additional consumables, etc. The MPCV will also be flown with a Service Module but that is not yet designed. The MPCV Service Module announced mass is 12,337 kg (27,198 lb) which would make it about twice the mass of the Apollo Service Module.
* One area where the MPCV capsule will eclipse the Apollo capsule is in electronics -- the MPCV electronics will certainly do far more than the earlier capsule's systems. Since the MPCV will carry far more boxes it will be interesting to see which one uses more total mass of avionics.
* The MPCV is being designed so it could do several missions; for instance, the re-entry heat shield is designed for a return from a higher speed lunar return trajectory.
* The Apollo Command Module was designed for a flight to the Moon, so it had more supplies. However, its avionics were based on the older vacuum tube era technology and they were far heavier while doing far less than current systems.
Charles Phillips has had a long career in the space field: he has worked in space operations since 1978, as an Air Force officer from 1978 until he retired in 2005 (working in space, communications, and maintenance), or as a NASA contractor, and he has been a writer all of that time. Now he finds the stories that people are interested in but might have been missed by other reporters.
uss carl vinson holly marie combs unc basketball college basketball gunsmoke papelbon papelbon
No comments:
Post a Comment
Note: Only a member of this blog may post a comment.