Monday, 23 November 2015

04.06.2101 - Venus Slingshot

By NASA/JPL ( [Public domain], via Wikimedia Commons

Distance: 29,919,574 km from Earth | Content Flag: Public

We’re passing by Venus in the first of the gravity assist manoeuvres, sometimes known as slingshots. These use a planet’s gravity to change a craft’s direction and increase velocity. Technically it’s the change caused by moving between frames of reference that can speed us up or slow us down.

It might seem counterproductive to head inwards when you’re actually trying to leave the solar system, but the extra energy gained by these flybys will help accelerate us to a speed sufficient to escape the Sun’s gravity.

So far on the journey we have used the main solar sail and the booster sled. We also gain speed by simply moving towards the Sun. The solar sail provides relatively little thrust on the inward approach, although it does help generate enough power to operate in full power mode. When we enter the cold dark of interstellar space, we’ll need to reduce our power consumption to a minimum by shutting down nonessential systems.

This booster frame has enough fuel to fly us to Jupiter where we will rendezvous with a new frame. UNSA mission control has confirmed that the new booster was successfully launched and is on its way to the parking orbit around Jupiter.

During this stage of the mission, the booster frame generates the majority of our thrust. With the sled, the sail and the gravity assist, we’re approaching a velocity of almost 30km per second. This is our first record-breaking of the mission as the fastest man-made object, although we are going to be travelling much faster than that when we reach interstellar space!

Flying by Venus and with no need to conserve power gives us an ideal opportunity to test our instrument packages. These are the various sensors providing us with information about our surroundings. A lot of data has already been accumulated about Earth’s hellish twin, which means we can compare our data and be sure that our instruments are reporting what we expect them to.

Venus is considered Earth’s twin mainly due to its similar size and mass, but in reality it’s a very different world to our home planet. From the optical sensors we see very little as the planet is swaddled in a dense beige atmosphere of carbon dioxide. Clouds of sulphur dioxide and sulphuric acid creating a greenhouse effect greater than any of gloomiest fates imagined for Earth from climate change. This gives Venus the hottest surface temperature of any planet in the solar system.

The radar mapping system confirms the smooth volcanic plains covering most of the surface. The topography visualisation shows the extensive volcano ranges and we can see far more than are active on Earth. In the northern hemisphere, we can see the continent Ishtar Terra with the highest mountain on Venus. To the south, we can see the second continental landmass. The optical sensors even detect the stream of ions being blasted from the upper atmosphere into a faint trail behind the planet.

Our magnetic field detectors show that Venus has a weak magnetic field, which is probably why the first Sun Dragon (now designated Sun Dragon A) skipped the planet on its journey to the Sun. Our scanners have greater resolution than the probes that visited the planet before. Satisfied with our tests, we transmitted the data we captured back to Earth.

Venus has already grown smaller as we speed towards the Sun. This is Seb signing off.


  1. How is the 2nd boosterframe at Jupiter getting it's speed to be able to rendezvous with our interstellar probe?

    1. It's already been launched and is propelled nuclear impulse engine (an advanced version of the ones used on the Mars Voyager). It's taking a more direct route to Jupiter than the Venti probe, along with gravity assists from Earth and Jupiter.

  2. When heading toward the sun with the sail deployed, do you tack against the wind like a sailing yacht?

    1. This question will be answered in the Q&A session - if you send your postal address to, we'll send you a mission patch.

    2. How would you communicate with another species? Would you use mathematics and pictures?

    3. Mathematics is considered one of the common elements that could be used in first contact - there's more detail on this later in the story.