Happy holidays and all that but let’s talk rockets, shall we? More specifically, let’s talk SpaceX’s historic vertical takeoff, vertical landing (VTVL)* of Falcon 9 on Sunday, December 21. The questions and comments have centered largely around who really is first to do VTVL (Vertical Takeoff, Vertical Landing) – Bezos’ Blue Origin or Musk’s SpaceX.
When I first heard of Blue Origin’s launch and landing, I didn’t even bother to check out the video because I thought SpaceX’s Grasshopper have done that already. I’m actually wrong, Grasshopper did eight successful VTVLs but the maximum height it reached was 744 m (2,440 ft) before it was retired.
So, For the category of VTVL rocket to reach space and successfully land, then yes, Blue Origin is the first of its kind. But when Jeff Bezos tweeted:
Congrats @SpaceX on landing Falcon’s suborbital booster stage. Welcome to the club!
— Jeff Bezos (@JeffBezos) December 21, 2015
A lot of people, including me, was incredulous. What club? Because SpaceX right now is on a league all its own.
Space vs. orbit
First of all, where does “space” begin?
Conventionally, the Kármán line at 100 km (62 mi) above sea level is used to define the beginning of outer space. And Blue Origin did breach space, reaching an altitude of 100.5 km before descending back to Earth.
But putting something into orbit is an entirely different kind of animal. First of all, the rocket does not just shoot straight up, it goes up and then goes sideways really, really fast after reaching a certain altitude. XKCD has done a great explainer on space vs. orbit here.
Getting to space needs ~Mach 3, but GTO orbit requires ~Mach 30. The energy needed is the square, i.e. 9 units for space and 900 for orbit.
— Elon Musk (@elonmusk) November 24, 2015
SpaceX Falcon 9 vs. Blue Origin’s Shepherd
- Speed – In order to for a rocket to go into orbit and to stay there, it has to reach horizontal speed of ~8 km/s. The International Space Station hovers above Earth at 330-410 km and it goes around the world every 90 minutes at a speed of 27,000 km/h or 7.5 km/s. SpaceX Falcon 9 first stage (the booster and the one landed) reached a max speed of around ~5,900 km/h while the second stage (the one that put the payload into orbit) reached a max speed of ~25,990 km/h**. Blue Origin reached a maximum speed of ~3,700 km/h.
- Fuel – Obviously, in order to achieve those speeds, the engines would need a LOT of fuel. In the case of SpaceX Falcon 9, the first stage booster not only need enough fuel to shoot the rocket into space, it needed enough fuel to reorient to come back down to earth, slowdown from its crazy speed, and maneuver to land in an upright position.
- Size and weight – SpaceX Falcon 9, at 70 m high, not only had to shoot the rocket into space and go into orbit, it had to carry a payload (or cargo) into space, in this case 11 satellites for ORBCOMM. Blue Origin’s New Shepard had no payload at all.
Space race is heating up
Now that we have that cleared up, it is great to see private companies focusing on space. Competition will yield the best technologies and the best practices and also prod the incumbents into action. And that is already happening.
An omnibus spending bill passed by Congress this month appropriates ~$55M and instructs NASA to develop a “prototype deep space habitation module” no later than 2018. It also requires NASA to submit a status report to Congress within 180 days of the bill’s enactment which could be early 2016.
Furthermore, SpaceX’s accomplishment could push Russia to reassess the costs of their own projects in order to maintain market share. The United Launch Alliance, a joint venture between Lockheed Martin Space Systems and Boeing Defense, Space and Security, uses Russian-built engines for most of its rockets. On December 23, 2015, the ULA announced that it had ordered 20 RD-180 engines to power up to 20 launches of the Atlas V rocket.
So, here’s to a wonderful 2016 and to hopefully more space exploration. And let me leave you with this:
* VTVL is a term used for a form of takeoff for rockets, not to be confused with VTOL (vertical take-off and landing) for aircraft – helicopters, fixed wing aircraft like the Harrier.
**Speed taken from SpaceX launch video