MOSCOW - Today, at 3:35 pm EDT (US) (early tomorrow morning local time), a Progress Space Freighter thundered into the sky above the Baikonure Cosmodrome on it's way to the International Space Station. Normally a Progress launch to ISS is something worth noting but really doesn't generate that much excitement. This one is different. Progress M-16M (the first M tells us that this is a M class Progress, the M at the end tells us that this is one of the new "digital" versions of the spacecraft and 16 denotes that this is the 16th flight of the digital Progress) is about to attempt something no other spacecraft has ever done - travel from Earth directly to ISS in just a few hours!
When a spacecraft is launched to ISS it normally enters orbit behind and lower that the station. The lower orbit, being closer to the Earth, is smaller and as a result, although the two spacecraft are traveling at the same speed, the spacecraft in the lower orbit can catch up to the one in the higher orbit eventually allowing the two to dock. This is why all spacecraft approach the orbiting outpost from beneath. The entire process takes about two days.
Progress M-16M is making use of new calculations that promise greater accuracy in the launch vehicle's trajectory. With the greater precision the spacecraft can be injected into an orbit that will guide the spacecraft to ISS within 6 hours of launch! Progress M-16M will dock with the station tonight at 9:24 pm EDT.
Ok so all of this is cool but why should the Russians be so concerned about how long their cargo takes to reach the ISS? The answer is their not. They are concerned about how long it takes their people to reach the station and if this works they intend to use the technique to send a manned Soyuz to the ISS on the same fast track. This is where the benefits come from.
As everyone who has ever seen one can tell you, the inside of a Soyuz is cramped - very cramped. By delivering the crew to the station withinn a few hours of launch, the Russian's not only limit the amount of time the crew needs to endure the cramped conditions but it also allows them to reduce the amount of food, water, oxygen, and other consumables that would normally be needed to support the crew during the two day commute. Less supplies means that they can carry more equipment (every pound you shed is one extra pound you can use for payload), you can also use less fuel (less weight equals less fuel), or just give the crew some breathing room!
Although this technology is new to the ISS program it is not new to spaceflight. Gemini spacecraft preformed rendezvous on flight day 1 and the first docking of two Soyuz spacecraft also happened on flight day 1. But as fate would have it it was decided by both the Americans and the Russians that constraints imposed on the geometry and the orbital mechanics were not worth the time savings. However with the retirement of the Space Shuttle and the new reliance on Soyuz spacecraft to service the ISS all that has changed and the Russians are ready to try it again.
Progress M-16M will be delivering 2 tons of cargo to the orbiting outpost. It is expected to remain docked for several months before being loaded with trash and intentionally destroyed during reentry. Good luck and God Speed Progress M-16M!
|Progress M-16M on the launch pad Photo Credit: SP Korolev Rocket and Space Corporation
The Progress docking will be carried live on the InterspaceNews home page tonight beginning at 9:00 pm EDT. http://www.interspacenews.com