Science Bear fruit

End of January, 1957; Baikonur Kosmodrone.

As Gene Kerman leaves the podium after explaining that the press conference was called due to the unfounded Illyrien claims that the recent landing on the Moon was a completely premature thing, that was not tested at all, and needlessly endangered Jebediah – he hands things over to Wernher von Kerman to explain the technical details of the mission.

“As you can see from this initial image, the Bear-1 was truly a massive rocket. Here it is compared to a Proton-1, which we still use this day to put small payloads, and single kerbonaut pods, into low earth orbit.”

Bear-1 scale
Proton-1 launcher next to the full Bear-1 rocket.

“As you can see, the Proton-1 is smaller than just the boosters of Bear-1, but moving beyond this, I will now go through the mission to explain why every aspect was well known and tested already. To make things more simple, I will be going through the mission backwards.”

“The last step is the return from the Moon, something that Valentina had accomplished on a previous mission. Knowing how much fuel it takes to make orbit, also lets us know how much fuel we needed to get back – so the return was already tested. Incidentally the command module turned out to have way too much fuel, as the return burn was planned taking the weight of the entire lander into account, when in fact it was left on the surface and in orbit respectively.”

“Before that, the challenge was to take off from the Moon and re-dock with the command module. Jebediah tested our intercept and docking procedures prior to launch. We know from previous landings on the Moon how much fuel it takes to get down – and with no atmosphere it’s the same to get up. We of course added a 10 % buffer of fuel here, just in case. As backup, we even had a RCS system that could technically manage the entire intercept and docking procedure.”

“But before intercepting and docking, we had to land – this had been done before with probes, and have both succeeded and failed on different occasions. To ensure our success here, we had built a brand new descent engine, one that could radically throttle down – all the way to 23 % thrust. While the lander still had a thrust to weight ration above one, firing the reaction control system retrograde put this below one. This way, we could aim the braking burn for completion a bit above the surface, and coast down to the surface using low thrust and the RCS system to maintain an exact descent speed.”

“This landing procedure allowed us to land at a mere 1.2 m/s, touching down so softly Jebediah could hardly feel it. Like the ascent stage, the landing stage had 10 % more fuel than we expected it to utilize. Both the descent and the ascent engine further made use of the same fuel mix, for increased flexibility. As Jebediah docked back in orbit, just below 5 % of the fuel were left – and the landing had even drawn a bit from the ascent stage, but not overly much, and we didn’t expect to utilize much of our ascent reserves.”

“The landing and the getting back to the command module were the most tricky parts of the mission, before that we had the Lunar orbit circularisation stage, which we’ve tried many times before, and was handled as a routine matter by the command module and its advanced AJ10 engine. The Trans Lunar Injection burn was also a routine, although the Bear-1 design had a separate LR-105 engine and fuel mix for this – which again had a 10 % reserve of fuel that weren’t utilized.”

“This merely left the orbital insertion from Earth, another operation that we have done many times, although never before have we placed a 130 tonnes payload into orbit. The first stage and boosters had a total of 8 F-1 engines combined, while the second stage doing the final orbital insertion had a single F-1 engine.”

“We are currently looking into a way to design future Lunar missions better, but that is going to require two things: Firstly we need more efficient engines for the upper stages of the rocket, and secondly we need it to be capable of at least limited restarts. That way we can use the same engines for circularisation around earth and the TLI burn and save the weight of lugging an entire extra engine into orbit. All in all, we expect that our next Lunar rocket will not be until we have developed these engines, and will be substantially lighter overall.”

With the presentation ended, Wernher left the podium to allow Gene to answer the various questions from the assembled reporters – most of which weren’t really of a technical nature either.

 

Advertisements

2 thoughts on “Science Bear fruit

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s