The Venus DRM mission timeline in the form of a mission architecture storyboard is shown in Figures 1 and 2, and consists of six key steps. The first figure shows the interplanetary trajectories and the various mission phases associated with the two launches, while the second figure provides a storyboard for the Entry, Descent and Inflation (EDI) and Entry, Descent and Landing (EDL) phases of the in situ elements.
Further details on the timeline are provided in Figure 3.
- Step 1: Carrier spacecraft launch: April 30, 2021 on an Atlas V 551 L/V (w/ 5 m diameter fairing); on a Type IV trajectory to Venus (arrives second).
- Step 2: Orbiter spacecraft launch: October 29, 2021 on an Atlas V 551 L/V (w/ 5 m diameter fairing); on a Type II trajectory to Venus (arrives first).
- Step 3: Orbiter arrives on April 6, 2022 (159-day cruise) Venus Orbit Insertion (VOI) maneuver; 300 km × 40000 km orbit for telecom relay support for (balloons & landers)
- Step 4: Carrier flyby on July 30, 2022 (436 days of cruise) Entry system #1 release: 20 days before carrier’s Venus flyby; Entry system #2 release: 10 days before carrier’s Venus flyby; Backup relay telecom support during lander’s lifetime
- Step 5: Staggered entry for entry systems (13 hours – one orbiter revolution); Entry, Descent, & Inflation (EDI) phases for the balloons; Entry, Descent, & Landing (EDI) phases for the landers.
- Step 5a: Pre-entry phase: entry system (w/ balloon & lander) cruises to Venus
- Step 5b: Atmospheric entry; entry heating; deceleration; Deployment of drogue parachute.
- Step 5c: Separation of aeroshell into two parts;Main chutes open for balloon & lander elements; Balloon released from storage container.
- Step 5d: Full balloon inflation in ~5 minutes
- Step 5e: Helium inflation system jettisoned; Balloon rises to 55.5 km equilibrium altitude; Lander continues its descent to the surface; descent science
- Step 5f: Balloon cord extended: One-month balloon science mission phase begins. Balloon data relayed to orbiter
- Step 5g: Lander reaches the ground after 1 hour of descent; Begin 5-hour surface science operations phase; Lander data relayed to orbiter
- Step 6: Orbiter completes relay telecom support: 6 months of aerobraking to 230 km circular orbit; 2 years of orbiter science operations in prime mission (sufficient propellant for 2-year extended mission)