Main Engine Cut Off

Spaceflight to Launch Brazil’s Amazonia-1

Representing the largest spacecraft Spaceflight has launched to date, Amazonia-1 weighs approximately 700 kilograms and is 1.7 meters in diameter and 2.6 meters tall. It will be the primary spacecraft on the PSLV mission, with the excess capacity filled by Spaceflight’s smallsat rideshare customers. Targeting mid-2020, Amazonia-1 will be deployed to a mean altitude 760 kilometers sun-synchronous orbit, while the additional secondary rideshare spacecraft will be deployed at a lower altitude.

Pretty cool to see Spaceflight sign a deal like this, where they book a full-size primary payload and will match secondary payloads with it on a dedicated launch. Seems like an attractive service for all parties, and I hope to see more of it in the future.

The Mystery of NROL-71

Dr. Marco Langbroek, with an intriguing post about the upcoming NROL-71 payload:

So, if NROL-71 is a new electro-optical reconnaissance satellite in the KH-11 series, it represents a serious deviation from past KH-11 missions. The apparent abandoning of a sun-synchronous polar orbit, is surprising, as such orbits are almost synonymous with Earth Reconnaissance. The “why” of a 74-degree orbit is mystifying too. If it does go into a 74-degree inclined orbit, it doesn't seem to be a “Multi-Sun-Synchonous-Orbit”.

Alternatives have been proposed. Ted Molczan has for example suggested that, perhaps, NROL-71 could be a reincarnation of the Misty stealth satellites, warning that the unexpected orbital inclination for NROL-71 might not be the only surprise.

Strap in for a fun ride, because Misty is a hell of a good story.

OneWeb Downsizes Initial Deployment

Caleb Henry for SpaceNews:

Greg Wyler, OneWeb’s founder, said the company will need only 600 satellites or so instead of 900 after ground tests of the first satellites demonstrated better than expected performance.

And later on in the article:

Wyler said 600 is the minimum needed for global coverage. Beyond that, OneWeb is deciding whether it will add 300 first-generation satellites or shift to a second-generation constellation designed to layer on more capacity.

Sounds like they are delaying 300 satellites, not specifically downsizing the entire constellation. If they’ve determined they don’t need 900 satellites worth of initial capacity, then that’s fine. But if they made the decision for some other reason like funding or schedule—which I have to believe is the case—then that’s not such a good sign, specifically for a company that is going through CEOs at a rate like they have been over the last few years.

SpaceShipTwo Reaches Space

I find Jonathan McDowell’s paper convincing, and I’ve always loved the X-15, so in the spirit of consistency, yes, SpaceShipTwo reached space today on its flight to 82.7 kilometers.

It was, unquestionably, a huge day for Virgin Galactic, a company that I’m not the biggest fan of, to say the least. I think their SpaceShipTwo architecture is a dead-end beyond flights like this, I find their engine choice questionable at best, and I have many issues with their PR.

But, damn, it’s really hard to talk shit on this view.

The one thing I’m left wondering after today is how the vehicle will do with a full load—passengers, seats, and all. It seems like they have some margin left on the engine burn duration, so with all that considered, is the 80 kilometer range their realistic target for customer flights?

Amateur Observers Searching for Chang’e 4 Find Nothing

Scott Tilley with a really interesting and very detailed post about the search for Chang’e 4:

Xinhua reported today that Chang’e 4 entered lunar orbit at about 08:39 UTC on Dec 12th.  No amateur observers reported observing the event; however, three highly competent amateur observers in Europe shared observations hours after the lunar orbit insertion burn was executed. No evidence of a signal from Chang’e 4 has been noted since my loss of signal earlier on Dec 12th.  I later conducted similar observations and searched around the Moon for the signal and found nothing we can relate to Chang’e 4. Only signals from Chang’e 5T-1 and Queqiao where noted.

He leaves us with a few theories towards the end of the post, but this doesn’t seem like a good sign.

T+104: Jake Robins

Jake Robins of WeMartians joins me to talk InSight, Mars EDL, and Mars 2020.

This episode of Main Engine Cut Off is brought to you by 33 executive producers—Kris, Pat, Matt, Jorge, Brad, Ryan, Jamison, Nadim, Peter, Donald, Lee, Jasper, Chris, Warren, Bob, Russell, John, Moritz, Joel, Jan, David, Grant, Mike, David, Mints, Joonas, Robb, and six anonymous—and 203 other supporters on Patreon.