What's this Emirates Mars Mission MOI fuss? I hear you asking. Well sit back and we'll take a ride together. You'll need to strap in...

#ArabsToMars

Basically, the #EmiratesMarsMission #HopeProbe arrives at Mars travelling at around 121,000 km/h. That's quite fast.
You'd sort of do Dubai to Abu Dhabi in three seconds at that kind of speed.

Or Dubai to New York in five minutes.
As we say, "quickie quickie"...

#ArabsToMars

At the end of its 493,500,000 km cruise from Earth to Mars, the #HopeProbe needs to hit a 'sweet spot' of +/- 300km and about 18,000 km/h.

So we're talking about a serious deceleration from that 121,000 km/h cruise speed, braking at around 3,800 km/h per minute.

#ArabsToMars

To slow down, Hope will fire its six Delta-V thrusters for 27 minutes.

That's a long time to fire a hot jet engine in space and it’s the first time they've been worked for this duration.

The stress is significant: it's the Mars mission's most dangerous operation.

#ArabsToMars

Worse, Hope is 11 minutes' radio distance away. So once the burn operation starts, any error message takes 11 minutes to reach us. By then it's too late to react.

The operation has to be autonomous: Hope has to error correct all by itself.

#ArabsToMars #LonelyLittleSpacecraft

So what can we do if something goes wrong?

Complex scripts are in place to anticipate errors. For instance, if a thruster blows out, Hope will compensate.

If we lose two thruster pairs, though, there's no hope for Hope. It's #GameOver.

#ArabsToMars #LonelyLittleSpacecraft

At the end of the MOI burn, at 6.57pm GST, Hope will be some 1,441 km above Mars and in its 'capture orbit' of 1,000 x 49,000 km. The Emirates would be the fifth player to reach Mars - a remarkable achievement for a nation 50 years young.

#ArabsToMars #PluckyLittleSpacecraft