PROLOGUE
Scroll to play the entire mission. The scrollbar is the mission clock.
ACT 1 · LAUNCH
A rideshare on a commercial rocket into a 1,000 km / 55° low Earth orbit — deep-space exploration that begins with a shared launch.
ACT 2 · TRANSFER
377 days on the real design trajectory: three continuous tangential-thrust arcs with automatic eclipse cutoffs — a 3,048-orbit spiral climb crossing the Van Allen belts again and again.
Total transfer duration378daysDESIGN · Delta-v4.11km/sDESIGN · Hall thruster60mNDESIGN
ACT 3 · STATION
Arrive early on the 31,600 km mission orbit — and wait for Apophis on the path it cannot avoid.
ACT 4 · ENCOUNTER
Closest encounter range7km · Encounter speed8.74km/s(spacecraft rel. to Apophis) · Peak resolution8cm/px
EPILOGUE
The Golden 2 Hours end, but the story doesn't — scroll on for the extended missions.
ACT 1 · LAUNCH
A rideshare on a commercial rocket into a 1,000 km / 55° low Earth orbit.
ACT 2 · TRANSFER
377 days on the real design trajectory: three continuous tangential-thrust arcs, 802 ignitions, a 3,048-orbit spiral climb (design values), with a delta-v of about 4.11 km/s.
ACT 3 · STATION
Arrive 17.9 days early on a mission orbit 38,015 km from Earth's center — matching Apophis's closest-approach altitude, with optical acquisition and tracking starting 2 million km out (design values).
ACT 4 · ENCOUNTER
2029-04-14 05:46 Beijing time: 7 km closest range, 8.74 km/s relative speed (spacecraft relative to Apophis), 8 cm/px peak resolution — an observation window of about 2 hours, fully autonomous.
EXTENDED MISSIONS
EXTENDED MISSION 01 · RADIATION BELT TOMOGRAPHY
On the way up, the spacecraft will cross the Van Allen radiation belts again and again — a region conventional missions steer well clear of. START turns it into a scientific opportunity: carrying a radiation-detection payload co-developed with Tsinghua's GRID (Tiange) team, it samples continuously across altitude through the 377-day, 3,048-orbit spiral transfer on the real trajectory, completing the world's first continuous tomographic survey of the radiation belts and delivering key measured data for protecting high-orbit satellite platforms.
Ionizing dose during transfer9.05krad(Si)DESIGN · Spiral revolutions3,048orbitsDESIGN
The spacecraft spirals from 1,000 km up to 31,600 km, crossing the inner and outer Van Allen belts again and again while sampling continuously along the way — thousands of orbital passes weave into a three-dimensional dose map of the belts.
Altitude 1,000 KM
Cumulative dose 0.00 krad
Belt transits 0
Dose and orbit counts are design values (3 mm equivalent aluminum shielding) · Payload co-developed with the GRID project · Drag the view to rotate
Where others steer clear, we chart the map.
Using the system's remaining margins, explore a new deep-space transfer route from high orbit to the Moon — extending the low-cost chain of "commercial LEO launch + electric-propulsion relay" all the way into cislunar space.
An "impact ejecta – flyby collection" concept: release an unpowered impactor, maneuver the main spacecraft clear and deploy an aerogel collection sail, then gather ejecta particles during a high-speed flyby — cutting the cost of acquiring extraterrestrial material by two orders of magnitude.